Positive and Negative Feedback Loops
A. Negative Feedback CO 2 O2O2 1. Control System that counteracts any change in the body that moves conditions above or below a set point. 2. Keeps internal environment stable. (Homeostasis!!) 3. Shuts off original stimulus or reduces intensity.
Negative Feedback Equilibrium Starting Situation
Example of Negative Feedback
Sympathetic Nervous System Parasympathetic Nervous System Fight Or Flight ResponseCalming return to Equilibrium
B. Positive Feedback 1.Control system that uses information from sensors to increase the rate of change away from set points. 2.Not common, only used when rapid change is needed. 3.Turns on Stimulus.
Positive Feedback Explosion Blocking No Equilibrium
Example of Positive Feedback MicrophoneAmplifier Explosion
Example of Positive Feedback
Pancreas Releases Insulin to Lower Blood Sugar Liver Releases Glucagon to Raise Blood Sugar
Positive Feedback Negative Feedback